using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(G(8));

         var randomChars = new List<char>();

        randomChars.Insert(0,'0');

        randomChars.Insert(1,'1');

        randomChars.Insert(2,'3');

        Console.WriteLine(new string(randomChars.ToArray()));

        randomChars.Insert(2,'2');

        Console.WriteLine(new string(randomChars.ToArray()));

    }

    private static string G(int length){

        string[] randomChars = new [] {

        "ABCDEFGHJKLMNOPQRSTUVWXYZ",    // uppercase 

        "abcdefghijkmnopqrstuvwxyz",    // lowercase

        "0123456789",                   // digits

        "!@#$%^?_-*+"                        // non-alphanumeric

    };

    Random rand = new Random(Environment.TickCount);

    List<char> chars = new List<char>();

​

   // if (opts.RequireUppercase)

        chars.Insert(rand.Next(0, chars.Count), 

            randomChars[0][rand.Next(0, randomChars[0].Length)]);

​

    //if (opts.RequireLowercase)       

          chars.Insert(rand.Next(0, chars.Count),

            randomChars[1][rand.Next(0, randomChars[1].Length)]);

​

​

    //if (opts.RequireDigit)

       chars.Insert(rand.Next(0, chars.Count),

            randomChars[2][rand.Next(0, randomChars[2].Length)]);

​

    //if (opts.RequireNonAlphanumeric)

       chars.Insert(rand.Next(0, chars.Count),

            randomChars[3][rand.Next(0, randomChars[3].Length)]);

​

​

    for (int i = chars.Count; i < length; i++)

    {

        string rcs = randomChars[rand.Next(0, randomChars.Length)];

        chars.Insert(rand.Next(0, chars.Count), 

            rcs[rand.Next(0, rcs.Length)]);

    }

​

    return new string(chars.ToArray());

    }

}